Oligoether derivatives of 1-phenoxyanthraquinone: Synthesis, photochromism, and complex formation with metal cations

Article abstract of DOI:10.1134/S1070428016080066

1-Phenoxyanthraquinone isomeric conjugates with tetraethylene glycol were prepared. Their photochromic properties and complex formation in solutions were quantitatively studied by spectrophotometry, quantum yields of the arylotropic photoisomerism and stability constants of complexes between para–ana-quinoid isomers and metal cations. The photochemical migration of a phenyl group considerably affects the complex stability thus providing the possibility to regard the synthesized compounds as photocontrolled ionophores. The structure of some complexes was investigated by X-ray diffraction (XRD) analysis and quantum-chemical simulation.

Full text of DOI:10.1134/S1070428016080066

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2016, Vol. 52, No. 8, pp. 1126–1136. © Pleiades Publishing, Ltd., 2016.
Original Russian Text © T.P. Mart’yanov, L.S. Klimenko, E.N. Ushakov, 2016, published in Zhurnal Organicheskoi Khimii, 2016, Vol. 52, No. 8,
pp. 1136–1146.
Oligoether Derivatives of 1-Phenoxyanthraquinone:
Synthesis, Photochromism, and Complex Formation
with Metal Cations
T. P. Mart’yanova*, L. S. Klimenkob, and E. N. Ushakova
a Institute of Problems of Chemical Physics, Russian Academy of Sciences,
pr. Academika Semenova 1, Chernogolovka, Moscow oblast, 142432 Russia
*e-mail: martyanov.t@gmail.com
b Yugra State University, Khanty-Mansiisk, Russia
Received March 17, 2016
Abstract—1-Phenoxyanthraquinone isomeric conjugates with tetraethylene glycol were prepared. Their
photochromic properties and complex formation in solutions were quantitatively studied by spectrophotometry,
quantum yields of the arylotropic photoisomerism and stability constants of complexes between para–ana-
quinoid isomers and metal cations. The photochemical migration of a phenyl group considerably affects the
complex stability thus providing the possibility to regard the synthesized compounds as photocontrolled
ionophores. The structure of some complexes was investigated by X-ray diffraction (XRD) analysis and
quantum-chemical simulation.
DOI: 10.1134/S1070428016080066
Photocontrolled ionophores are a special class of
optical molecular sensors where the chromophore
fragment is capable of reversible structural changes
under light resulting in the variation of the ionophore
group ability to bind metal cations and other charged
species. Such compounds may be used in developing
photopharmacologic preparations [1], photocontrolled
extraction, photorefractive and photosensitive ion-
conducting materials [2]. Nowadays in the design of
the photocontrolled ionophores several types of
reversible photoreactions are utilized: The photo-
isomerization of geometric isomers of diarylethylenes,
azobenzene, and thioindigo, valence photoisomerism
of spiro compounds and chromenes, photocyclization
of dihetarylethenes, etc. [3–6].
qualitative level, demonstrating the fundamental
possibility of the action of photocontrolled ionophore,
yet the quantitative explorations are scarce. We
synthesized a series of new photochromic derivatives
of 1-phenoxyanthraquinone containing in their compo-
sition a ionophore fragment, tetraethylene glycol
methyl ether, and estimated experimentally the
reciprocal influence of the arylotropic photoisomeri-
zation and the complex formation with metal cations.
Proceeding from dichloroanthraquinones 1a–1c
through an intermediate stage of diphenoxy derivatives
2a–2c formation we obtained derivatives of tetra-
ethylene glycol and 1‑phenoxyanthraquinone 3a–3c
(Scheme 2). In the first stage the chlorine atoms in
compounds 1a–1c were replaced by phenoxy groups
No examples are known of the synthesis of
photocontrolled ionophores underlain by the reversible
photoarylotropic transition characteristic of peri-
aryloxy-para-quinones (Scheme 1) [7]. The advan-
tages of this photochromic process consist in a large
range of color changes, high quantum yields, and a
sufficient thermal stability of the photoform.
Scheme 1.
O
OAr
OAr
O
hv1
hv2
The majority of studies on the complex formation
control with light are carried out only on the
O
O
ana-quinone
para-quinone
1126

OLIGOETHER DERIVATIVES OF 1-PHENOXYANTHRAQUINONE: SYNTHESIS
1127
Scheme 2.
OH
O
O
O
O
OPh
O
O
OPh
O
NaH, THF
O
OPh
OPh
O
CH3
O
2a
4
3a
OH
O
O
R3
O
Cl
O
O
OPh
O
O
2 PhOH
Cu, KOH
NaH, THF
R2
O
R1
OPh
OPh
O
H3C
H3C
O
O
O
O
O
1a_1c
2b
4
3b
OH
O
O
O
R1 = Cl, R2 = R3 = H (a);
R1 = R3 = H, R2 = Cl (b);
R1 = R2 = H, R3 = Cl (c).
O
O
OPh
O
OPh
4
O
NaH, THF
O
2c
3c
applying a common procedure [8]. In the second stage
one of the obtained phenoxy groups was substituted
via a nucleophilic mechanism with the tetraethylene
glycol monomethyl ether in the presence of sodium
hydride in tetrahydrofuran. This synthetic procedure
proved to be more convenient than the successive
substitution of chlorine atoms (first with the tetra-
ethylene glycol monomethyl ether, then with the
phenoxy group) due to the easy procedure of reaction
products isolation.
Analogous spectral transitions were observed at the
irradiation of the solution of compound 3b. At the
irradiation of isomer 3с the initial spectrum was not
D
2
2
D
0.8
0.8
0.6
0.6
hv
hν
1
1
00..44
The electronic spectrum of compound 3а in
acetonitrile contains a characteristic longwave absorp-
tion band, λmax 391 nm (Fig. 1). At irradiation of the
solution of compound 3a with UV light (λ 365 nm) the
intensity of this band decreases and a new absorption
band appears, λmax 487 nm, corresponding to the ana-
quinoid structure (anthracene-1,10-dione) [9]. The
subsequent irradiation of the solution with a green
light (λ 546 nm) led to the recovery of the spectrum of
the initial para-quinoid isomer due to the reverse
reaction of phenyl group phototransfer (Scheme 1).
0.2
0.2
0.0
0.0
λ/nm
λ / нм
300
400
500
300
500
400
Fig. 1. Variation of the electron absorption spectrum of
compound 3a in MeCN (сL 1·10–4 mol L–1, l 1 cm) at
stationary irradiation with UV light, λ 365 nm, intensity
2.51·10–9 mol/(cm2·s). 1, spectrum of initial para-quinoid
isomer 3a; 2, spectrum of para‒ana-photostationary state.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 52 No. 8 2016

MART’YANOV et al.
1128
Table 1. Absorption bands maxima for para- and ana-quinoid isomers (λp and λа, nm) and quantum yields of the direct and
reverse reaction of para‒ana-photoisomerization (φp–a and φa–p) for phenoxyanthraquinones 3a–3c and their calcium
complexes in acetonitrile
Parameterа
3a
3a·Ca2+
3b
3b·Ca2+
3c
3c·Ca2+
λп
391
396
374
386
374
374
λa
487
503
476
495
506
–
–
–
–
φp–a
φa–p
0.057
0.011
0.0088
0.015
0.049
0.0099
0.0057
0.018
–
a
The error in measuring the quantum yields did not exceed ±20%.
completely recovered because of the chemical
instability of the ana-quinoid photoform that converted
in a compound possessing an orange fluorescence (λmax
~415 nm). The ana-isomer 3с was likely relatively
initial para-isomer and the spectra of two photo-
stationary states obtained at irradiation of compound
3а with light at wavelengths of λ 365 and 436 nm. It
was assumed that the ratio of the quantum yields of the
direct and reverse para‒ana-photoisomerization (φp–a
and φa–p) was independent of the radiation wavelength.
The φp–a and φa–p values were evaluated from the
kinetics of the absorption spectra observed at the
stationary irradiation with UV light, λ 365 nm, of the
solution of compound 3а.
easily hydrolyzed forming
a
derivative of 1-
hydroxyanthraquinone 4 (Scheme 3). As mentioned in
published data [9, 10], derivatives of anthracene-1,10-
dione may be highly reactive with respect to
nucleophilic agents, in particular, to water molecules
present in the solvent.
The absorption spectrum of the ana-quinoid
The spectral characteristics of photoisomers and
photoisomer was calculated using the spectrum of the
quantum yields φp–a and φa–p for compounds 3a and 3b
Scheme 3.
H3C
O
H3C
O
H3C
O
O
O
O
OH
O
O
OPh
O
4
OPh
O
4
4
hv1
hv2
H2O
–PhOH
O
O
4
3c
ana-3c
–Ca2+
Ca2+
Ca2+ –Ca2+
O
O
O
O
O
Ca2+
Ca2+
O
O
Δ, <10 s
O
O
O
O
O
O
O
O
O
3c·Ca2+
ana-3c·Ca2+
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 52 No. 8 2016

OLIGOETHER DERIVATIVES OF 1-PHENOXYANTHRAQUINONE: SYNTHESIS
1129
and their calcium complexes in acetonitrile are
compiled in Table 1. We failed to measure reliably the
φp–a and φa–p values for compound 3c containing the
polyether substituent in the position 8 due to the
chemical instability of the photoform. The degassing
of the solvents of compounds 3a–3c did not affect the
kinetics of the photoreaction.
was investigated by spectrophotometric titration. The
addition of alkali and alkaline earth metal perchlorates
to the solutions of compounds 3a–3c causes a red shift
of the longwave absorption band (Fig. 2) indicating the
coordination of the cation not only to the oxygen
atoms of the polyether chain but also to the heteroatom
of the electron-acceptor part of the chromoionophore
[4, 5, 15], namely, to the carbonyl oxygen atom of the
anthraquinone scaffold. The stability constants and the
absorption spectra of the complexes were calculated by
parametric matrix simulation of the data of the
spectrophotometric titration [16]. In all cases the
experimental data were well described by the simplest
model of complex formation (1):
The quantum yields of the direct para‒ana-
photoisomerization reaction of compounds 3a and 3b
in the polar acetonitrile are considerably lower than of
various 1-phenoxyanthraquinone derivatives in
nonpolar solvents and polymer matrices (φp–a 0.2–0.7
[11, 12]). This is likely due to the nonpolar biradical
structure of the transition state suggested for the
arylotropic photoisomerization [13].
Photochemistry of complexes. Complexes 3a·Ca2+
and 3b·Ca2+ same as compounds 3a and 3b exhibit a
photochromism (Scheme 1). At the complex formation
of ligands 3a and 3b with Ca2+ φp–a significantly
decreases, and φa–p somewhat grows (Table 1). The
main cause of the observed changes consists
apparently in the interaction of the metal cation in the
complexes 3a·Ca2+ and 3b·Ca2+ with the carbonyl
oxygen atom resulting in the electron density
redistribution in the anthraquinone scaffold.
K
L + Mn+
LMn+
(1)
Here L is ligand, Mn+ is the metal cation, K is the
equilibrium constant (stability constant of the
complex).
Stability constants and spectrophotometric charac-
teristics of the complexes are listed in Table 2. Ligands
3a–3c coordinate the metal cations with six oxygen
Table 2. Stability constants of complexes of compounds 3a
–3c with cations of alkali and alkaline earth metals and
spectrophotometric characteristics of these ligands and their
complexesа
The unique feature of isomer 3c consists in the
promotion at the complex formation with Ca2+ of the
isomerization in the dark of the ana-quinoid into the
para-quinoid form (Scheme 3). This effect was
unexpected since for quite a number of 1-phenoxy-
anthraquinone photochromic derivatives previously
studied [7] both the direct and reverse para‒ana-
isomerization occurred only under photochemical
conditions. Occurring in the dark arylotropic rearran-
gements of 1-amino-4-phenoxy-anthracene-9,10-dione
and 4-amino-9-phenoxyanthracene-1,10-dione in the
presence of AlCl3 were a rare exclusion [14].
Compound
no.
3a
3a·Na+
3a·Ca2+
3b
3b·Na+
3b·Ca2+
3c
3c·Na+
3c·Mg2+
3c·Ca2+
3c·Sr2+
3c·Ba2+
ε
max×10–3,
Log K
λ
max, nm
Δλ, nm
L mol–1 cm–1
5.34
391
391
397
374
377
388
374
376
397
386
385
383
2.86
6.18
5.35
0
5.06
+6
7.64
2.84
6.25
8.01
+3
7.64
+14
6.34
A fast dark ana‒para-isomerization in the complex
3c·Ca2+ is evidently due to the direct interaction of the
metal cation in the complex with the ana-isomers with
the oxygen atom of the phenoxy group (Scheme 3).
This interaction causes the weakening of the О–Ph
bond and reduces the activation energy of the ana‒
para-isomerization. Because of the high rate constant
of the reverse dark reaction (>0.1 s–1) the photoinduced
para‒ana-isomerization of the complex 3c·Ca2+ is not
observed under the stationary irradiation conditions.
2.90
3.22
6.41
6.47
6.06
6.83
+2
+23
+12
+11
+9
6.27
6.76
7.42
7.31
In MeCN (content of H2O <0.03 vol %), 25°C, сL 2·10–5 (cell
а
5 cm), сM 0–0.01 mol L–1; λmax is the position of the absorption
band maximum; εmax is the molar absorption coefficient at λmax
;
Δλ = λmax(complex) – λmax(ligand); K = [L·Mn+]/([L]·[Mn+]),
total error in measuring K does not exceed ±20% (the standard
deviation for K in the parametric simulation of the data of
spectrophotometric titration has been no more than 1%).
Complex formation. Complex formation of
compounds 3a–3c with metal cations in acetonitrile
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 52 No. 8 2016

MART’YANOV et al.
the derivatives of benzo-18-crown-6-ether. In Fig. 3
1130
0.8
0.8
D
D
1 – 3a
1 – 3a
the dependences are shown of the logarithm of the
stability constants (log K) on the effective metal cation
radius (rM) for the complexes of compound 3c and of
2-aminonaphthoquinone 5 substituted at the atom N
with a benzo-18-crown-6-ether fragment. The data for
compound 5 we have obtained earlier [17]. Values of
rM are taken from [18].
2+
2+
2 – 3a · Ca
2 – 3a·Ca
0.6
0.6
0.4
0.4
2
2
1
1
0.2
0.2
O
O
O
O
O
O
Cl
0.0
0.0
λ / нм
300
300
350
350
400
450
450
500
400
500
N
H
λ, nm
O
O
D
D
1 – 3b
1 – 3b
2 – 3b · Ca
log K
5
2+
0.6
0.6
2+
2 – 3b·Ca
lgK
9
9
2
2
5
8
8
7
7
0.4
0.4
6
6
3с
5
5
1
1
0.2
0.2
5
3c
4
4
3
3
2
2
+
2+
Ca22++ Na+
Sr2+
2+
2+
Mg2+
Ba2+
0.0
0.0
Ca Na
Sr
Mg
λ / нм
1
1
300
300
350
350
400
450
450
500
500
rM / Å
400
λ, nm
0.7
0.8
0.9
1.0
1.1
1.2
1.3
1.4
0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4
rM, Å
D
0.6
0.6
D
Fig. 3. Dependence of log K on the effective metal cation
radius rM for complexes of compounds 5 and 3c with
cations of alkaline earth metals and sodium in MeCN.
1 – 3c
1 – 3c
2 – 3c · Ca
2 – 3c·Ca
2+
2+
2
0.4
0.4
2
1
O1
1
0.2
0.2
O2
Na
O2
O1
0.0
0.0
Na
λ / нм
500
300
300
350
350
400
400
450
450 λ/nm 500
λ, nm
Fig. 2. Electron absorption spectra of systems 3–Ca(ClO4)2
in MeCN (сL 2×10–5 mol L–1, l 5 cm) depending on the
metal salt concentration, сM (0–1.2)×10–4 mol L–1.
Fig. 4. The structure of complex 3c·NaClO4 in a single
crystal. Coordination bonds are shown by dashed lines. The
atoms are represented as thermal ellipsoids of 50%
probability. Hydrogen atoms, perchlorate anions, and
solvent molecules are not shown. Carbon atoms in the first
ethylene unit of the oligoether chain are disordered.
atoms (5 ether and 1 carbonyl), therefore it is reasonab-
le to compare their complex-forming properties with
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 52 No. 8 2016

OLIGOETHER DERIVATIVES OF 1-PHENOXYANTHRAQUINONE: SYNTHESIS
1131
Table 3. Crystallographic data and parameters of X-ray
diffraction experiment with complex 3c·NaClO4
The log K values for crown ether 5 are essentially
higher than for compound 3c since the crown ethers in
contrast to acyclic analogs are preliminary structurally
organized for the complex formation. Complexes with
Mg2+ form exclusion. The effective radius of the cation
is considerably smaller than the radius of the cavity of
18-crown-6-ether. In this case the key factor governing
the stability of the complex becomes the conforma-
tional flexibility of the oligoether. Acyclic oligoether
fragment of compound 3c possesses a higher confor-
mational flexibility than the crown ether fragment of
compounds 5, therefore the log K value for 3с·Mg2+ is
significantly larger than for 5·Mg2+.
Empiric formula
C34H25ClNaO12
684.00
M
Crystal system
monoclinic
Space group
a, Å
P21/c
6.8431(5)
30.1507(19)
15.2064(9)
93.938(6)
3130.0(3)
4
b, Å
c, Å
β, deg
V, Å3
Z
Complex 3c·NaClO4 we succeeded to grow as
single crystals. It was established by XRD analysis that
this complex formed a dimer (Fig. 4, Table 3) where
each sodium cation was bound with five polyether
heteroatoms and two carbonyl oxygen atoms, and the
latter belonged to different molecules. The
intramolecular bond is formed through the carbonyl
group in the position 9 of the anthraquinone scaffold
[O2···Na1 2.331(4)Å], and the intermolecular bond
involves the carbonyl group in the position 10
[О1···Na1 2.335(4) Å]. Anthraquinone fragments are
located in parallel planes with a distance between them
being equal 3.412(6) Å. In acetonitrile solutions at the
ligand 3a–3c concentrations ~1×10–4 mol L–1 the dimer
complexes do not form.
Ρ
calc, g/cm–3
1.451
F(000)
1412
μ(MoKα), mm–1
Crystal size, mm3
Temperature, K
Scanning area by θ, deg
0.203
0.3 × 0.2 × 0.15
100.0(2)
2.77‒26.32
–8 ≤ h ≤ 8, –23 ≤ k ≤ 37,
–18 ≤ l ≤ 18
Range of reflection indices
Measured reflections
13328
6362 (Rint 0.0761)
3324
The data on the complex formation of the ana-
quinoid photoisomers of compounds 3a and 3b with
Na+ and Ca2+ in acetonitrile were obtained using
spectrophotometric titration of the mixtures of para-
and ana-isomers with metal perchlorates. Stability
constants and absorption spectra of the ana-quinone
complexes were calculated by the parametric matrix
simulation of the spectrophotometric titration data in
the terms of two equilibrium reactions (2, 3), where P
and A were the molecules of para- and ana-isomers
respectively, Mn+ was the metal cation, KP and KA were
the equilibrium constants.
Independent reflections
Reflections with I > 2σ(I)
Number of refined parameters
406
R-Factors for reflections with
I > 2σ(I)
R1 0.1104, wR2 0.2125
R-Factors for all reflections
R1 0.1866, wR2 0.2535
Quality factor with respect to F2
1.022
Residual electron density
‒0.763 / 0.826
(min/max), e/Å3
KP
n+
P + Mn+
A + Mn+
P M
.
para- and ana-isomers of compoundss 3a and 3b with
Na+ and Ca2+ obtained by the above described proce-
dure are listed in Table 4. The absorption bands of the
complexes of para- and ana-isomers 3a with Ca2+ are
shown in Fig. 5 and compared with the spectra of free
isomers.
2
3
KA
n+
.
A M
Photoionochromic processes involving compound
3a are presented in Scheme 4 (analogously for
compound 3b). The stability constants and the spec-
trophotometric characteristics of the complexes of
ana-Quinoid photoisomers 3a and 3b, same as the
initial para-isomers, are characterized at the complex
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 52 No. 8 2016

MART’YANOV et al.
1132
Scheme 4.
O
O
O
O
O
O
hv1
hv2
O
O
O
CH3
O
CH3
4
4
3a
ana-3a
KA
+M
KP
+M
–M
–M
O
O
O
O
O
hv1
hv2
O
O
O
O
O
M
M
O
O
O
O
O
O
3a·M
ana-3a·M
M = Na+, Ca2+.
formation of small red shifts in the absorption spectra.
The complexes of ana-isomers 3a and 3b exceed in the
stability the corresponding complexes of the para-
isomers (KA of complex 3a·Ca2+ is three times larger
than KP). Apparently, the phenyl group migration
results in an increased electron density on the carbonyl
oxygen atom located in the peri-position to the
polyether chain providing a stronger interaction
between this atom and the metal cation. Taking into
consideration the reversibility of the para‒ana-photo-
isomerism compounds 3a and 3b may be regarded as
photocontrolled ionophores.
In both structures a coordination bond exists
between the calcium cation and the oxygen atom of the
carbonyl group of the anthraquinone residue in
keeping with the conclusions based on the spectro-
photometric data. In both cases this bond is shorter
than the coordination bonds with the polyether oxygen
atoms (2.36 Å against 2.45–2.51 Å for para-3a·Ca2+,
2.33 Å against 2.45–2.55 Å for ana-3a·Ca2+). The ana-
isomer compared with the para-isomer is characterized
not only by a shorter C=O···Ca2+ bond but also by a
larger negative charge on the carbonyl oxygen atom
coordinated to Ca2+ (–0.711 against –0.675). In other
words, the calculations predict the stronger
coordination bond C=O···Ca2+ in the complex with the
ana-isomer. This prediction is in agreement with the
experimental fact: the para‒ana-photoisomerization of
complex 3a·Ca2+ results in a triple increase in the
stability constant.
Quantum-chemical simulation. In Fig. 6 the
structures of para- and ana-quinoid isomers of
complex 3a·Ca2+ in acetonitrile are presented
calculated by the quantum-chemical method B3LYP/6-
31G(d)/C-PCM (see EXPERIMENTAL).
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OLIGOETHER DERIVATIVES OF 1-PHENOXYANTHRAQUINONE: SYNTHESIS
1133
Table 4. Stability constants of complexes of para- and ana-
isomers 3a and 3b with sodium and calcium cations,
spectrophotometric characteristics of the isomers and their
complexesа
Therefore the complex formation of ligands 3а–3с
with metal cations significantly affects the quantum
yield of the arylotropic photoisomerization due to the
involvement of the carbonyl group of the quinone
along with the polyester fragment in the coordination
of the metal cation. In phenoxyanthraquinones 3а and
3b containing a polyether chain in the position 4 or 5
the transition from para- to ana-quinoid isomer led to
the growing stability of complexes with metal cations
due to the increased negative charge on the carbonyl
oxygen atom involved in the complex formation.
Considering the photochemical reversibility of the
arylotropic rearrangement these compounds may be
regarded as photocontrolled ionophores. The complex
formation with metal cations of phenoxyanthraquinone
3с containing a polyether chain in the position 8
promotes the dark reaction of ana‒para-isomerization
due to the coordination of the metal cation to the
phenoxy oxygen atom.
ε
max·10–3,
Compound no. Log K
λ
max, nm
Δλ, nm
L·mol–1·cm–1
3a
391
488
391
489
397
503
374
476
377
480
388
5.34
12.6
5.35
12.6
5.06
12.3
7.64
11.5
8.01
13.7
7.65
ana-3a
3a·Na+
2.87
2.98
6.27
0
+1
ana-3a·Na+
3a·Ca2+
+6
ana-3a·Ca2+ 6.74
+15
3b
ana-3b
3b·Na+
2.93
3.14
6.19
+3
+4
ana-3b·Na+
3b·Ca2+
+14
ana-3b·Ca2+ 6.58
495
14.6
+19
а
In MeCN (content of H2O <0.03 vol %), 25°C, сL 2×10–5 (cell
EXPERIMENTAL
5 cm), сM 0–0.01 mol L–1; λmax is the position of the absorption
band maximum; εmax is the molar absorption coefficient at λmax
;
IR spectra were recorded on
a
Fourier
Δλ = λmax(complex) – λmax(ligand); K = [L·Mn+]/([L]·[Mn+]),
total error in measuring K does not exceed ±20% (the standard
deviation for K in the parametric simulation of the data of
spectrophotometric titration has been no more than 1%).
spectrophotometer Bruker Alpha FT-IR in the mode of
multiple attenuated total internal reflection. NMR
spectra were registered on a spectrometer Bruker
Avance III (500 MHz). Chemical shifts were measured
from the solvent signals [19]. Electron absorption
spectra were taken on a spectrophotometer Specord-
M40 using quartz cells with the optical path l 1 and
5 cm. All cells were equipped with good ground-glass
stoppers. The stationary irradiation was carried out
with a high pressure mercury lamp DRSh-250.
Separate lines of the spectrum of this lamp (λ 365, 436,
and 546 nm) were filtered by glass optical filters. The
intensity of UV light (λ 365 nm) was measured by
chemical actinometry.
1 – P (3a)
12
12
2 – PM (3a·Ca2+)
3 – A (ана-3a)
10
10
4 – AM (ана-3a·Ca2+)
8
8
6
6
4
4
3
3
4
4
2
2
2
2
1
1
λ / нм
0
0
300
300
350
350
400
400
450
450
500
500
550
550
600
600
3a·Ca2+
ana-3a·Ca2+
λ, nm
Fig. 6. Spatial arrangement of complexes 3a·Ca2+ and ana-
3a·Ca2+ in acetonitrile calculated by the method B3LYP/6-
31G(d)/C-PCM (hydrogen atoms are not shown).
Fig. 5. Electron absorption spectra of compound 3a (1), its
photoform ana-3a (3), and complexes 3a·Ca2+ (2) and ana-
3a·Ca2+ (4) in MeCN.
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MART’YANOV et al.
1134
Acetonitrile (Kriokhrom, grade 0, “specially pure,”
1,5-Diphenoxyanthracene-9,10-dione (2b). Yield
1.21 g (77%), mp 159–161°C. IR spectrum, ν, cm–1:
3090, 3063, 3036, 3006 (C–H), 1663 (C=O), 1578
(C=C). 1H NMR spectrum (CDCl3), δ, ppm: 7.05–7.09
m (2Н, Н2',6'), 7.17 t.t (1Н, Н4', J 7.7, 1.1 Hz), 7.23 d.d
(1Н, Н2, J 8.3, 1.2 Hz), 7.36–7.42 m (2Н, Н3',5'), 7.63–
7.68 m (1Н, Н3), 8.05 d.d (1Н, Н4, J 7.7, 1.2 Hz). 13С
NMR spectrum (CDCl3), δ, ppm: 119.13 (C2',6'),
122.97 (C4), 123.45 (C4'), 124.14 (C2), 125.33 (C3),
130.15 (C3',5'), 135.08 (C13), 137.18 (C14), 156.66 (C1'),
157.19 (C1), 181.71 (C9). Found, %: C 79.70; H 4.391.
C26H16O4. Calculated, %: C 79.58; H 4.11.
H2O content <0.03 vol %), ethyl acetate “chemically
pure,” dichloromethane “chemically pure,” toluene
“specially pure,” tetrahydrofuran (Lab-Scan, HPLC,
99.8%), sodium hydride in mineral oil (Sigma-Aldrich,
60%), tetraethylene glycol monomethyl ether (Sigma-
Aldrich), and all initial dichloroanthraquinones of
“pure” grade were used without additional purification.
Ethanol was dried with preliminary calcined (220°С)
CuSO4 followed by distillation. Salts Mg(ClO4)2, Ca
(ClO4)2, Sr(ClO4)2, and Ba(ClO4)2 were dried in a
vacuum at 230°С, NaClO4, at 170°С. The chroma-
tography was carried out on columns packed with
silica gel (Merck, 40–63 µm) and by TLC on standard
Silufol UV-254 plates. Elemental analysis was
performed on an instrument vario MICRO cube.
1,8-Diphenoxyanthracene-9,10-dione (2c). Yield
1.21 g (77%), mp 145–147°C. IR spectrum, ν, cm–1:
3080 sh, 3065, 3037, 3012 (C–H), 1670 (C=O), 1584,
1571 (C=C). 1H NMR spectrum (CDCl3), δ, ppm: 7.02
–7.07 m (2Н, Н2',6'), 7.10–7.15 m (1Н, Н4'), 7.22 d.d
(1Н, Н2, J 8.3, 1.1 Hz), 7.31–7.37 m (2Н, Н3',5'), 7.60 t
(1Н, Н3, J 8.0 Hz), 8.04 d.d (1H, Н4, J 7.7, 1.1 Hz). 13С
NMR spectrum (CDCl3), δ, ppm: 119.75 (C2',4',6'),
122.04 (C4), 124.16 (C2), 125.80 (C3), 130.01 (C3',5'),
134.04 (C13), 135.02 (C14), 156.63 (C1'), 157.50 (C1),
181.14 (C9), 183.26 (C10). Found, %: C 79.88; H
4.306. C26H16O4. Calculated, %: C 79.58; H 4.11.
Diphenoxyanthraquinones 2a–2c. General pro-
cedure. A mixture of 1.11 g (4 mmol) of dichlo-
roanthraquinone 1a–1c, 3 g (32 mmol) of phenol, 0.9 g
(16 mmol) of potassium hydroxide, and 0.06 g
(0.5 mmol) of copper powder was heated at 130°С
with a vigorous stirring for 2 h. After cooling to room
temperature the black resinous reaction mixture was
diluted with 50 mL of 10% KOH solution. The
separated precipitate was filtered off and washed first
with 100 mL of 5% KОН, and then with water till
neutral washings. The solid residue was dried at 90°С
for 3 h, then it was dissolved in 20 mL of toluene. The
solution was chromatographed on a column packed
with SiO2 (40–63 µm), eluent toluene. The first light-
yellow zone contained the monosubstituted anthrax-
quinone with an impurity of the hydroxy derivative.
Next the target product was eluted as a wide yellow
zone. This fraction was collected, evaporated, and
recrystallized from ethanol to obtain diphenoxyanthra-
quinones 2a–2c as yellow crystalline substances.
Oligoether derivatives of 1-phenoxyanthraqui-
none (3a–3c). General procedure. A solution of 0.39 g
(1 mmol) of diphenoxyanthraquinone 2a–2c and 0.2 mL
(1 mmol) of tetraethylene glycol monomethyl ether in
15 mL of THF was slowly added to slurry of 0.06 g
(1.5 mmol) of sodium hydride in 5 mL of THF. The
reaction mixture was boiled for 10 h at vigorous
stirring. After cooling to room temperature 100 mL of
water and several drops of conc. hydrochloric acid was
added. The product was extracted with dichlo-
romethane (3 × 100 mL). The combined extracts were
dried with calcined MgSO4, the solvent was distilled
off on a water bath. The residue was dissolved in 10 mL
of toluene and the solution was chromatographed on a
column packed with SiO2 (40–63 µm). Eluting with
toluene provided a yellow fraction of the initial diphe-
noxyanthraquinone. The elution was continued with a
mixture toluene‒ethanol, 5 : 1. The collected wide
yellow fraction contained the reaction product. On
distilling off the solvent the crude reaction product was
dissolved in 10 mL of ethyl acetate and was passed
through a thick silica gel bed (eluent ethyl acetate).
The edges of the yellow zone were discarded. The
obtained fraction was evaporated, the residue was
dried in a vacuum. We obtained yellow viscous fluids.
Yields were calculated with respect to the reacted
1,4-Diphenoxyanthracene-9,10-dione (2a). Yield
1.18 g (75%), mp 125–127°C. IR spectrum, ν, cm–1:
3091, 3068 sh, 3057, 3037, 3012 (C–H), 1666 (C=O),
1
1589, 1567 (C=C). H NMR spectrum (CDCl3), δ,
ppm: 7.01–7.07 m (2Н, Н2',6'), 7.10–7.16 m (1Н, H4'),
7.27 s (1H, H2), 7.34–7.40 m (2H, H3',5'), 7.70–7.76 m
(1H, H7), 8.15–8.20 m (1H, H8). 13С NMR spectrum
(CDCl3), δ, ppm: 118.23 (C2',6'), 123.71 (C2), 125.92
(C4'), 126.93 (C8), 128.58 (C7), 130.14 (C3',5'), 133.88
(C13), 134.11 (C12), 152.82 (C1'), 157.25 (C1), 182.13
(C9). Found, %: C 79.65; H 4.313. C26H16O4.
Calculated, %: C 79.58; H 4.11.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 52 No. 8 2016

OLIGOETHER DERIVATIVES OF 1-PHENOXYANTHRAQUINONE: SYNTHESIS
1135
initial diphenoxyanthraquinone. The assignment of
signals in the 1Н and 13С NMR spectra was carried out
basing on 2D spectra 1H-1H COSY and 1H-13C HSQC.
Нγ), 3.89–3.94 m (2Н, Нβ), 4.22–4.26 m (2Н, Нα),
7.02–7.06 m (2Н, Н2',6'), 7.10–7.15 m (1Н, Н4'), 7.23
d.d (1Н, Н2, J 8.2, 1.2 Hz), 7.33–7.38 m (3Н, Н7,3',5'),
7.58 t (1Н, Н3, J 7.7 Hz), 7.63 t (1Н, Н6, J 8.0 Hz),
7.88 d.d (1Н, Н5, J 7.7, 1.1 Hz), 8.00 d.d (1Н, Н4, J
7.7, 1.2 Hz). 13С NMR spectrum (CDCl3), δ, ppm:
59.14 (CH3), 69.59 (Cθ), 69.96 (Cη), 70.60 (Cξ), 70.62
(Cε), 70.69 (Cδ), 70.80 (Cγ), 71.08 (Cβ), 72.04 (Cα),
119.23 (C2',6'), 119.77 (C5), 120.73 (C4), 122.15 (C7),
123.83 (C2), 124.42 (C4'), 126.30 (C6), 126.49 (C3),
129.98 (C3',5'), 133.75 (C12), 134.14 (C13), 134.95 (C11),
134.97 (C14), 156.75 (C1'), 157.09 (C1), 159.07 (C8),
181.53 (C9), 183.62 (C10). Found, %: C 68.45; H
6.146. C29H30O8. Calculated, %: C 68.76; H 5.97.
1-(2,5,8,11-Tetraoxatridecan-13-yloxy)-4-pheno-
xyanthracene-9,10-dione (3a). Yield 0.20 g (65%).
IR spectrum, ν, cm–1: 3069 (C–H), 2920 sh, 2875 (Caliph
–
H), 1672 (C=O), 1594, 1568 (C=C). 1H NMR
spectrum (CDCl3), δ, ppm: 3.35 s (3Н, СН3), 3.51–
3.55 m (2Н, Нθ), 3.61–3.72 m (8Н, Нδ,ε,ξ,η), 3.83–3.87
m (2Н, Нγ), 3.99–4.03 m (2Н, Нβ), 4.30–4.34 m (2Н,
Нα), 6.94–6.98 m (2Н, Н2',6'), 7.08 t.t (1Н, Н4', J 7.6,
1.1 Hz), 7.30–7.35 m (3Н, Н3',5',2), 7.39 d (1Н, Н3, J
9.2 Hz), 7.68 t.d (1Н, Н6, J 7.4, 1.6 Hz), 7.72 t.d (1Н,
Н7, J 7.5, 1.6 Hz), 8.11 d.d (1Н, Н5, J 7.5 Hz), 8.18 d.d
(1Н, Н8, J 7.5 Hz). 13С NMR spectrum (CDCl3), δ,
ppm: 59.15 (CH3), 69.81 (Cθ), 70.37 (Cη), 70.64 (Cξ),
70.71 (Cε), 70.75 (Cδ), 70.82 (Cγ), 71.20 (Cβ), 72.06
(Cα), 117.39 (C2',6'), 122.58 (C3), 123.03 (C2), 123.58
(C4'), 126.48 (C5), 126.72 (C6,8), 129.62 (C7), 129.94
(C3',5'), 133.47 (C14), 133.75 (C13), 133.88 (C11), 134.49
(C12), 149.92 (C1'), 156.38 (C1), 158.00 (C4), 182.54
(C10), 182.58 (C9). Found, %: C 68.71; H 6.272.
C29H30O8. Calculated, %: C 68.76; H 5.97.
Crystalline complex of compound 3с with NaClO4.
A solution of 100 mg of compound 3с and 24 mg of
sodium perchlorate in a mixture of 2 mL of acetonitrile
and 1 mL of toluene in a vial of 7 mL capacity was
evaporated in air till the appearance of the first visible
crystal (~3 days). Then the vial was air-tight closed
and was stored in the dark for 1 week. The precipitated
crystals were filtered off, washed with toluene, and
dried in air for 2 days. Found, %: C 55.28; H 5.111.
C29H30ClNaO12. Calculated, %: C 55.38; H 4.81.
1-(2,5,8,11-Tetraoxatridecan-13-yloxy)-5-pheno-
xyanthracene-9,10-dione (3b). Yield 0.21 g (60%). IR
spectrum, ν, cm–1: 3068, 3037 (C–H), 2874 (Caliph–H),
1673 (C=O), 1585 (C=C). 1H NMR spectrum (CDCl3),
δ, ppm: 3.35 s (3Н, СН3), 3.51–3.55 m (2Н, Нθ), 3.61–
3.72 m (8Н, Нδ,ε,ξ,η), 3.83–3.87 m (2Н, Нγ), 4.00–4.04
m (2Н, Нβ), 4.30–4.35 m (2Н, Нα), 7.02–7.06 m (2Н,
Н2',6'), 7.14 t.t (1Н, Н4', J 7.4, 1.1 Hz), 7.19 d.d (1Н, Н2,
J 8.3, 1.1 Hz), 7.32 d.d (1Н, Н6, J 8.4, 0.8 Hz), 7.34–
7.39 m (2Н, Н3',5'), 7.61–7.68 m (2Н, Н7,3), 7.87 d.d (1Н,
Н8, J 7.7, 0.9 Hz), 8.04 d.d (1Н, Н4, J 7.7, 1.1 Hz). 13С
NMR spectrum (CDCl3), δ, ppm: 59.13 (CH3), 69.57
(Cθ), 69.61 (Cη), 70.60 (Cξ), 70.67 (Cε), 70.71 (Cδ),
70.79 (Cγ), 71.22 (Cβ), 72.03 (Cα), 119.03 (C2',6'),
119.08 (C8), 120.28 (C4), 121.50 (C6), 122.76 (C2),
123.39 (C4'), 124.00 (C7), 124.94 (C3), 130.06 (C3',5'),
134.86 (C11), 135.14 (C13), 137.12 (C12), 137.49 (C14),
156.69 (C1'), 156.91 (C1), 159.33 (C5), 181.96 (C10),
182.13 (C9). Found, %: C 68.46; H 6.260. C29H30O8.
Calculated, %: C 68.76; H 5.97.
XRD analysis of the complex 3c·NaClO4 was
carried out on a diffractometer XCalibur (coordinate
detector EOS, MoKα-radiation, λ 0.71073 Å, 100 K).
The structure was solved by the direct method and
refined in the anisotropic approximation of the thermal
parameters of all nonhydrogen atoms (calculations
were performed applying SHELXTL software [20]).
The key crystallographic parameters and the details of
the XRD experiment are presented in Table 3.
The XRD results of complex 3c·NaClO4 are
deposited in the Cambridge Crystallographic Data
Center (CCDC 1452284) and may be obtained free at
the address www.ccdc.cam.ac.uk/data_request/cif.
Quantum-chemical simulation. First we performed
the conformational search for the para- and ana-
quinoid isomers of complex 3a·Ca2+ by the molecular
mechanics method (force field MMFF94s [21]).
Geometric structures of the selected conformers (about
20 in each case) were optimized by the method of the
theory of density functional (functional PBE [22],
basis set 3ζ, quantum-chemical program Priroda [23]).
Then several most probable conformations were
optimized by the method B3LYP/6-31G(d) using the
program package GAUSSIAN 09 [24]. For the
conformations of para- and ana-isomers 3a·Ca2+ with
1-(2,5,8,11-Tetraoxatridecan-13-yloxy)-8-pheno-
xyanthracene-9,10-dione (3c). Yield 0.17 g (66%). IR
spectrum, ν, cm–1: 3068, 3033 (C–H), 2921 sh, 2879
1
(Caliph–H), 1674 (C=O), 1585 (C=C). H NMR spec-
trum (CDCl3), δ, ppm: 3.35 s (3Н, СН3), 3.50–3.53 m
(2Н, Нθ), 3.59–3.63 m (8Н, Нδ,ε,ξ,η), 3.74–3.77 m (2Н,
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 52 No. 8 2016

MART’YANOV et al.
1136
10. Klimenko, L.S., Leonenko, Z.V., and Gritsan, N.P.,
Mol. Cryst. Liq. Cryst., 1991, vol. 297, p. 181.
11. Babailov, S.P., Klimenko, L.S., and Mainagashev, I.Ya.,
the lowest energy using B3LYP total optimization of
the geometric structures in acetonitrile was carried out.
The solvent effect was accounted for using the
continual solvation model C-PCM [25]. The stationary
character of the structure obtained by the method
B3LYP/6-31G(d)/C-PCM was confirmed by the
calculation of the vibrational spectra (no oscillations
with an imaginary frequency were present). The
effective atomic charges were calculated by the
method NPA (Natural population analysis) [26].
J. Struct. Chem., 2006, vol. 47, p. 663.
12. Eroshkin, V.P., Fokin, E.P., Volkov, A.I., Andreeva, T.A.,
Klimenko, L.S., Dolgikh, Yu.K., and Simonenko, A.F.,
Zh. Fiz. Khim., 1991, vol. 65, p. 1479.
13. Born, R., Fischer, W., Heger, D., Tokarczyk, B.,
and Wirz, J., Photochem. Photobiol. Sci., 2007, vol. 6,
p. 552.
14. Gerasimenko, Yu.E., Poteleshchenko, N.T.,
and Romanov, V.V., Zh. Org. Khim., 1980, vol. 16,
p. 2014.
The study was carried out under a financial support
of the Russian Foundation for Basic Research (grant
no. 16-33-00708 mol_а). The authors express their
gratitude to Candidate of Chemical Sciences
D.V. Korchagin (Institute of Problems of Chemical
Physics, Russian Academy of Sciences) for performing
XRD experiment.
15. Löhr, H.-G. and Vögtle, F., Acc. Chem. Res., 1985,
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Pershina, Yu.V., Alfimov, M.V., Barigilletti, F.,
Flamigni, L., and Balzani, V., J. Phys. Chem. A, 1999,
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